Microsoft Access 2010 Bible

Part IV: Professional Database Development

988

Property Let

The Property Let procedure assigns a value to a property. The property’s value is passed into the

procedure as an argument, and the value is then assigned to the class module’s private variable that

stores the property’s value.

The following example is a prototype for any Property Let procedure:

Public Property Let <PropertyName>(Value As <DataType>)

<PrivateVariable> = Value

End Property

Tip
The property’s argument can be named anything you want. I always use Value as the argument name.
Consistently using Value is simpler than assigning a meaningful name to the argument and is consistent with
how property values are assigned to built-in Access properties.

The following example is from the Employee class module:

Public Property Let LastName(Value As String)

m_LastName = Left$(Value, 20)

End Property

This small example hints at the power of property procedures. Notice that the Value argument is

a string. The statement within the property procedure assigns only the 20 leftmost characters of

the Value argument to the m_LastName variable. This is because the LastName field in the

Northwind Employees table only accepts 20 characters. Many database systems generate errors if

more characters are sent to a field than the field can hold.

Tip
Adding a little bit of logic to a property procedure can go a long way toward bulletproofing an application.

Property Set

The syntax of Property Set is parallel to the Property Let procedure. The only difference is

that the argument is an object data type, and the VBA Set keyword is used for the assignment

within the body of the Property Set. The following is an example of hypothetical Property

Set procedure that accepts a recordset object and assigns it to a private variable named m_

Products:

Public Property Set Products(Value As ADO.Recordset)

If Not Value Is Nothing Then

Set m_Products = Value

End If

End Property

In this small example, the argument is validated before it is assigned to the private variable.